1. Field of the Invention
The present invention relates to a control lever system for performing change-overs of the drive line such as changing over the final clutch of a vehicle between two-wheel drive and four-wheel drive, changing over the front differential gear unit between locked and free statuses and changing over the rear differential gear unit between locked and free statuses.
2. Description of Background Art
As an example of a control lever system, a change over with a single control lever between high speed and low speed forward and backward running is known. In such a control lever system, the driver, while holding the steering wheel with the left hand, operates the control lever with the right hand and changes over the transmission to the low speed forward position by shifting the lever from the neutral position rightward and forward. The transmission is changed over to the high speed forward position by shifting the lever from the neutral position leftward and forward. The transmission is changed over to the backward running position by shifting from the neutral position rightward and behind while applying downward pressure (see Japanese Application Laid-Open No. 2002-307969 for instance).
In recent years, along with the diversification of vehicles, there have emerged vehicles which permit change-overs of the drive line such as changing over the final clutch of a vehicle between two-wheel drive and four-wheel drive, changing over the front differential gear unit between locked and free statuses and changing over the rear differential gear unit between locked and free statuses. Such a vehicle is equipped with a control lever for changing over between two-wheel drive and four-wheel drive, a control lever for changing over the front differential gear unit between locked and free statuses, and a control lever for changing over the rear differential gear, each independent of others. In selecting a function of the drive line of the vehicle, the driver has to separately operate the control levers and to conceive a combination of different traveling modes with the control levers.
On the other hand, Japanese Application Laid-Open No. 2002-307969 cited above is not concerned with changing over between two-wheel drive and four-wheel drive, changing over the front differential gear between locked and free statuses and changing over the rear differential gear between locked and free statuses.